1. Field
Example embodiments relate to purification methods of block copolymers and methods of forming patterns using the block copolymers.
2. Description of the Related Art
Photolithography has been widely used for forming a pattern of a semiconductor device. However, a pattern having a critical dimension below, e.g., 40 nm is difficult to obtain through the photolithography process due to a resolution limit. Thus, a double patterning method (e.g., using at least two mask types) has been researched. However, the double patterning method may require complicated steps and excessive process cost.
Accordingly, a direct self assembly (DSA) method using a block copolymer has been developed. In the DSA method, the block copolymer having a high purity may be needed.